Pavel Emelyanov | 7eb9515 | 2007-10-15 02:31:52 -0700 | [diff] [blame] | 1 | /* |
| 2 | * inet fragments management |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Authors: Pavel Emelyanov <xemul@openvz.org> |
| 10 | * Started as consolidation of ipv4/ip_fragment.c, |
| 11 | * ipv6/reassembly. and ipv6 nf conntrack reassembly |
| 12 | */ |
| 13 | |
| 14 | #include <linux/list.h> |
| 15 | #include <linux/spinlock.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/timer.h> |
| 18 | #include <linux/mm.h> |
Pavel Emelyanov | 321a3a9 | 2007-10-15 02:38:08 -0700 | [diff] [blame^] | 19 | #include <linux/random.h> |
Pavel Emelyanov | 7eb9515 | 2007-10-15 02:31:52 -0700 | [diff] [blame] | 20 | |
| 21 | #include <net/inet_frag.h> |
| 22 | |
Pavel Emelyanov | 321a3a9 | 2007-10-15 02:38:08 -0700 | [diff] [blame^] | 23 | static void inet_frag_secret_rebuild(unsigned long dummy) |
| 24 | { |
| 25 | struct inet_frags *f = (struct inet_frags *)dummy; |
| 26 | unsigned long now = jiffies; |
| 27 | int i; |
| 28 | |
| 29 | write_lock(&f->lock); |
| 30 | get_random_bytes(&f->rnd, sizeof(u32)); |
| 31 | for (i = 0; i < INETFRAGS_HASHSZ; i++) { |
| 32 | struct inet_frag_queue *q; |
| 33 | struct hlist_node *p, *n; |
| 34 | |
| 35 | hlist_for_each_entry_safe(q, p, n, &f->hash[i], list) { |
| 36 | unsigned int hval = f->hashfn(q); |
| 37 | |
| 38 | if (hval != i) { |
| 39 | hlist_del(&q->list); |
| 40 | |
| 41 | /* Relink to new hash chain. */ |
| 42 | hlist_add_head(&q->list, &f->hash[hval]); |
| 43 | } |
| 44 | } |
| 45 | } |
| 46 | write_unlock(&f->lock); |
| 47 | |
| 48 | mod_timer(&f->secret_timer, now + f->ctl->secret_interval); |
| 49 | } |
| 50 | |
Pavel Emelyanov | 7eb9515 | 2007-10-15 02:31:52 -0700 | [diff] [blame] | 51 | void inet_frags_init(struct inet_frags *f) |
| 52 | { |
| 53 | int i; |
| 54 | |
| 55 | for (i = 0; i < INETFRAGS_HASHSZ; i++) |
| 56 | INIT_HLIST_HEAD(&f->hash[i]); |
| 57 | |
| 58 | INIT_LIST_HEAD(&f->lru_list); |
| 59 | rwlock_init(&f->lock); |
| 60 | |
| 61 | f->rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^ |
| 62 | (jiffies ^ (jiffies >> 6))); |
| 63 | |
| 64 | f->nqueues = 0; |
| 65 | atomic_set(&f->mem, 0); |
| 66 | |
Pavel Emelyanov | 321a3a9 | 2007-10-15 02:38:08 -0700 | [diff] [blame^] | 67 | init_timer(&f->secret_timer); |
| 68 | f->secret_timer.function = inet_frag_secret_rebuild; |
| 69 | f->secret_timer.data = (unsigned long)f; |
| 70 | f->secret_timer.expires = jiffies + f->ctl->secret_interval; |
| 71 | add_timer(&f->secret_timer); |
Pavel Emelyanov | 7eb9515 | 2007-10-15 02:31:52 -0700 | [diff] [blame] | 72 | } |
| 73 | EXPORT_SYMBOL(inet_frags_init); |
| 74 | |
| 75 | void inet_frags_fini(struct inet_frags *f) |
| 76 | { |
Pavel Emelyanov | 321a3a9 | 2007-10-15 02:38:08 -0700 | [diff] [blame^] | 77 | del_timer(&f->secret_timer); |
Pavel Emelyanov | 7eb9515 | 2007-10-15 02:31:52 -0700 | [diff] [blame] | 78 | } |
| 79 | EXPORT_SYMBOL(inet_frags_fini); |
Pavel Emelyanov | 277e650 | 2007-10-15 02:37:18 -0700 | [diff] [blame] | 80 | |
| 81 | static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f) |
| 82 | { |
| 83 | write_lock(&f->lock); |
| 84 | hlist_del(&fq->list); |
| 85 | list_del(&fq->lru_list); |
| 86 | f->nqueues--; |
| 87 | write_unlock(&f->lock); |
| 88 | } |
| 89 | |
| 90 | void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f) |
| 91 | { |
| 92 | if (del_timer(&fq->timer)) |
| 93 | atomic_dec(&fq->refcnt); |
| 94 | |
| 95 | if (!(fq->last_in & COMPLETE)) { |
| 96 | fq_unlink(fq, f); |
| 97 | atomic_dec(&fq->refcnt); |
| 98 | fq->last_in |= COMPLETE; |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | EXPORT_SYMBOL(inet_frag_kill); |